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Zhang Z, Xing J, Li X, Lu X, Liu G, Qu Y, Zhao J. Review of research progress on the production of cellulase from filamentous fungi. Int J Biol Macromol 2024; 277:134539. [PMID: 39122065 DOI: 10.1016/j.ijbiomac.2024.134539] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2024] [Revised: 07/29/2024] [Accepted: 08/04/2024] [Indexed: 08/12/2024]
Abstract
Cellulases have been widely used in many fields such as animal feed, textile, food, lignocellulose bioconversion, etc. Efficient and low-cost production of cellulases is very important for its industrial application, especially in bioconversion of lignocellulosic biomass. Filamentous fungi are currently widely used in industrial cellulase production due to their ability to secrete large amounts of active free cellulases extracellularly. This review comprehensively summarized the research progress on cellulases from filamentous fungi in recent years, including filamentous fungi used for cellulase production and its modification strategies, enzyme compositions, characterization methods and application of fungal cellulase systems, and the production of fungal cellulase includes production processes, factors affecting cellulase production such as inducers, fermentation medium, process parameters and their control strategies. Also, the future perspectives and research topics in fungal cellulase production are presented in the end of the review. The review helps to deepen the understanding of the current status of fungal cellulases, thereby promoting the production technology progress and industrial application of filamentous fungal cellulase.
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Affiliation(s)
- Zheng Zhang
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao 266237, China
| | - Jing Xing
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao 266237, China
| | - Xuezhi Li
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao 266237, China
| | - Xianqin Lu
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao 266237, China
| | - Guodong Liu
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao 266237, China
| | - Yinbo Qu
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao 266237, China.
| | - Jian Zhao
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao 266237, China.
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Liu J, Chen M, Gu S, Fan R, Zhao Z, Sun W, Yao Y, Li J, Tian C. Independent metabolism of oligosaccharides is the keystone of synchronous utilization of cellulose and hemicellulose in Myceliophthora. PNAS NEXUS 2024; 3:pgae053. [PMID: 38380057 PMCID: PMC10877092 DOI: 10.1093/pnasnexus/pgae053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Accepted: 01/29/2024] [Indexed: 02/22/2024]
Abstract
The effective utilization of cellulose and hemicellulose, the main components of plant biomass, is a key technical obstacle that needs to be overcome for the economic viability of lignocellulosic biorefineries. Here, we firstly demonstrated that the thermophilic cellulolytic fungus Myceliophthora thermophila can simultaneously utilize cellulose and hemicellulose, as evidenced by the independent uptake and intracellular metabolism of cellodextrin and xylodextrin. When plant biomass serviced as carbon source, we detected the cellodextrin and xylodextrin both in cells and in the culture medium, as well as high enzyme activities related to extracellular oligosaccharide formation and intracellular oligosaccharide hydrolysis. Sugar consumption assay revealed that in contrast to inhibitory effect of glucose on xylose and cellodextrin/xylodextrin consumption in mixed-carbon media, cellodextrin and xylodextrin were synchronously utilized in this fungus. Transcriptomic analysis also indicated simultaneous induction of the genes involved in cellodextrin and xylodextrin metabolic pathway, suggesting carbon catabolite repression (CCR) is triggered by extracellular glucose and can be eliminated by the intracellular hydrolysis and metabolism of oligosaccharides. The xylodextrin transporter MtCDT-2 was observed to preferentially transport xylobiose and tolerate high cellobiose concentrations, which helps to bypass the inhibition of xylobiose uptake. Furthermore, the expression of cellulase and hemicellulase genes was independently induced by their corresponding inducers, which enabled this strain to synchronously utilize cellulose and hemicellulose. Taken together, the data presented herein will further elucidate the degradation of plant biomass by fungi, with implications for the development of consolidated bioprocessing-based lignocellulosic biorefinery.
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Affiliation(s)
- Jia Liu
- Key Laboratory of Engineering Biology for Low-carbon Manufacturing, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
- National Technology Innovation Center of Synthetic Biology, Tianjin 300308, China
| | - Meixin Chen
- Key Laboratory of Engineering Biology for Low-carbon Manufacturing, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
- National Technology Innovation Center of Synthetic Biology, Tianjin 300308, China
| | - Shuying Gu
- Key Laboratory of Engineering Biology for Low-carbon Manufacturing, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
- National Technology Innovation Center of Synthetic Biology, Tianjin 300308, China
| | - Rui Fan
- Key Laboratory of Engineering Biology for Low-carbon Manufacturing, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
- National Technology Innovation Center of Synthetic Biology, Tianjin 300308, China
| | - Zhen Zhao
- Key Laboratory of Engineering Biology for Low-carbon Manufacturing, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
- National Technology Innovation Center of Synthetic Biology, Tianjin 300308, China
| | - Wenliang Sun
- Key Laboratory of Engineering Biology for Low-carbon Manufacturing, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
- National Technology Innovation Center of Synthetic Biology, Tianjin 300308, China
| | - Yonghong Yao
- Key Laboratory of Engineering Biology for Low-carbon Manufacturing, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
- National Technology Innovation Center of Synthetic Biology, Tianjin 300308, China
| | - Jingen Li
- Key Laboratory of Engineering Biology for Low-carbon Manufacturing, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
- National Technology Innovation Center of Synthetic Biology, Tianjin 300308, China
| | - Chaoguang Tian
- Key Laboratory of Engineering Biology for Low-carbon Manufacturing, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
- National Technology Innovation Center of Synthetic Biology, Tianjin 300308, China
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Maués DB, Maraschin JC, Duarte DÂ, Antoniêto ACC, Silva RN. Overexpression of the Transcription Factor Azf1 Reveals Novel Regulatory Functions and Impacts β-Glucosidase Production in Trichoderma reesei. J Fungi (Basel) 2023; 9:1173. [PMID: 38132774 PMCID: PMC10744372 DOI: 10.3390/jof9121173] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2023] [Revised: 12/02/2023] [Accepted: 12/05/2023] [Indexed: 12/23/2023] Open
Abstract
The fungus Trichoderma reesei is an essential producer of enzymes that degrade lignocellulosic biomass to produce value-added bioproducts. The cellulolytic system of T. reesei is controlled by several transcription factors (TFs) that efficiently regulate the production of these enzymes. Recently, a new TF named Azf1 was identified as a positive regulator of cellulase expression. Here, we investigated novel regulatory functions of Azf1 by its overexpression. In the mutant strain OEazf1, overexpression of azf1 was achieved under both repression and induction conditions. Although azf1 was more abundant in transcript and protein, overexpression of this TF did not activate transcription of the cellulase gene in the presence of the repressor glucose, suggesting that Azf1 may be subject to posttranslational regulation. In cellulose, the expression of swo, encoding the accessory protein swollenin, and the β-glucosidases cel1a, cel1b, cel3b, and cel3g increases in the early stages of cultivation. The increased production of these β-glucosidases increases the hydrolysis rate of cellobiose and sophorose, which activates carbon catabolite repression (CCR) and causes repression of cellulase genes and the regulator Xyr1 in the later stages of cultivation. Moreover, overexpression of azf1 led to increased cellulase activity in T. reesei during long-term cultivation in cellulose and sugarcane bagasse. Our results provide new insights into the mechanisms regulating Azf1 and novel genes that are important targets of this TF. This work contributes to a better understanding of the complex mechanisms regulating cellulase expression in T. reesei. It will contribute to the development of strains with higher production of these essential enzymes.
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Affiliation(s)
| | | | | | | | - Roberto N. Silva
- Department of Biochemistry and Immunology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto 14049-900, SP, Brazil; (D.B.M.); (J.C.M.); (D.Â.D.); (A.C.C.A.)
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Zhang S, Ni D, Zhu Y, Xu W, Zhang W, Mu W. A comprehensive review on the properties, production, and applications of functional glucobioses. Crit Rev Food Sci Nutr 2023:1-14. [PMID: 37819266 DOI: 10.1080/10408398.2023.2261053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/13/2023]
Abstract
Glucobiose is a range of disaccharides consisting of two glucose molecules, generally including trehalose, kojibiose, sophorose, nigerose, laminaribiose, maltose, cellobiose, isomaltose, and gentiobiose. The difference glycosidic bonds of two glucose molecules result in the diverse molecular structures, physiochemical properties and physiological functions of these glucobioses. Some glucobioses are abundant in nature but have unconspicuous roles on health like maltose, whereas some rare glucobioses display remarkable biological effects. It is unpractical process to extract these rare glucobioses from natural resources, while biological synthesis is a feasible approach. Recently, the production and application of glucobiose have attracted considerable attention. This review provides a comprehensive overview of glucobioses, including their natural sources and physicochemical properties like structure, sweetness, digestive performance, toxicology, and cariogenicity. Specific enzymes used for the production of various glucobioses and fermentation production processes are summarized. Additionally, their versatile functions and broad applications are also introduced.
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Affiliation(s)
- Shuqi Zhang
- State Key Laboratory of Food Science and Resoruces, Jiangnan University, Wuxi, Jiangsu, China
| | - Dawei Ni
- State Key Laboratory of Food Science and Resoruces, Jiangnan University, Wuxi, Jiangsu, China
| | - Yingying Zhu
- State Key Laboratory of Food Science and Resoruces, Jiangnan University, Wuxi, Jiangsu, China
| | - Wei Xu
- State Key Laboratory of Food Science and Resoruces, Jiangnan University, Wuxi, Jiangsu, China
| | - Wenli Zhang
- State Key Laboratory of Food Science and Resoruces, Jiangnan University, Wuxi, Jiangsu, China
| | - Wanmeng Mu
- State Key Laboratory of Food Science and Resoruces, Jiangnan University, Wuxi, Jiangsu, China
- International Joint Laboratory on Food Safety, Jiangnan University, Wuxi, Jiangsu, China
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Dong CD, Patel AK, Madhavan A, Chen CW, Singhania RR. Significance of glycans in cellulolytic enzymes for lignocellulosic biorefinery - A review. BIORESOURCE TECHNOLOGY 2023; 379:128992. [PMID: 37011847 DOI: 10.1016/j.biortech.2023.128992] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2023] [Revised: 03/28/2023] [Accepted: 03/29/2023] [Indexed: 05/03/2023]
Abstract
Lignocellulosic (LC) biomass is the most abundant renewable resource for mankind gravitating society towards sustainable solution for energy that can reduce the carbon footprint. The economic feasibility of 'biomass biorefinery' depends upon the efficiency cellulolytic enzymes which is the main crux. Its high production cost and low efficiencies are the major limitations, that need to be resolved. As the complexity of the genome increases, so does the complexity of the proteome, further facilitated by protein post-translational modifications (PTMs). Glycosylation is regarded the major PTMs and hardly any recent work is focused on importance of glycosylation in cellulase. By modifying protein side chains and glycans, superior cellulases with improved stability and efficiency can be obtained. Functional proteomics relies heavily on PTMs because they regulate activity, localization, and interactions with protein, lipid, nucleic acid, and cofactor molecules. O- and N- glycosylation in cellulases influences its characteristics adding positive attributes to the enzymes.
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Affiliation(s)
- Cheng-Di Dong
- Institute of Aquatic Science and Technology, National Kaohsiung University of Science and Technology, Kaohsiung City, Taiwan; Department of Marine Environmental Engineering, National Kaohsiung University of Science and Technology, Kaohsiung 81157, Taiwan; Sustainable Environment Research Center, National Kaohsiung University of Science and Technology, Kaohsiung City 81157, Taiwan
| | - Anil Kumar Patel
- Institute of Aquatic Science and Technology, National Kaohsiung University of Science and Technology, Kaohsiung City, Taiwan; Department of Marine Environmental Engineering, National Kaohsiung University of Science and Technology, Kaohsiung 81157, Taiwan; Centre for Energy and Environmental Sustainability, Lucknow 226 029, India
| | - Aravind Madhavan
- School of Biotechnology, Amrita Vishwa Vidyapeetham, Amritapuri, Kollam, Kerala 690 525, India
| | - Chiu-Wen Chen
- Institute of Aquatic Science and Technology, National Kaohsiung University of Science and Technology, Kaohsiung City, Taiwan; Department of Marine Environmental Engineering, National Kaohsiung University of Science and Technology, Kaohsiung 81157, Taiwan; Sustainable Environment Research Center, National Kaohsiung University of Science and Technology, Kaohsiung City 81157, Taiwan
| | - Reeta Rani Singhania
- Institute of Aquatic Science and Technology, National Kaohsiung University of Science and Technology, Kaohsiung City, Taiwan; Department of Marine Environmental Engineering, National Kaohsiung University of Science and Technology, Kaohsiung 81157, Taiwan; Centre for Energy and Environmental Sustainability, Lucknow 226 029, India.
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Aggarwal S, Dorairaj S, Adlakha N. Stoichiometric balance ratio of cellobiose and gentiobiose induces cellulase production in Talaromyces cellulolyticus. BIOTECHNOLOGY FOR BIOFUELS AND BIOPRODUCTS 2023; 16:48. [PMID: 36927685 PMCID: PMC10018878 DOI: 10.1186/s13068-023-02296-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2023] [Accepted: 03/02/2023] [Indexed: 03/18/2023]
Abstract
BACKGROUND The exact mechanism by which fungal strains sense insoluble cellulose is unknown, but research points to the importance of transglycosylation products generated by fungi during cellulose breakdown. Here, we used multi-omics approach to identify the transglycosylation metabolites and determine their function in cellulase induction in a model strain, Talaromyces cellulolyticus MTCC25456. RESULTS Talaromyces sp. is a novel hypercellulolytic fungal strain. Based on genome scrutiny and biochemical analysis, we predicted the presence of cellulases on the surface of its spores. We performed metabolome analysis to show that these membrane-bound cellulases act on polysaccharides to form a mixture of disaccharides and their transglycosylated derivatives. Inevitably, a high correlation existed between metabolite data and the KEGG enrichment analysis of differentially expressed genes in the carbohydrate metabolic pathway. Analysis of the contribution of the transglycosylation product mixtures to cellulase induction revealed a 57% increase in total cellulase. Further research into the metabolites, using in vitro induction tests and response surface methodology, revealed that Talaromyces sp. produces cell wall-breaking enzymes in response to cellobiose and gentiobiose as a stimulant. Precisely, a 2.5:1 stoichiometric ratio of cellobiose to gentiobiose led to a 2.4-fold increase in cellulase synthesis. The application of the optimized inducers in cre knockout strain significantly increased the enzyme output. CONCLUSION This is the first study on the objective evaluation and enhancement of cellulase production using optimized inducers. Inducer identification and genetic engineering boosted the cellulase production in the cellulolytic fungus Talaromyces sp.
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Affiliation(s)
- Shivam Aggarwal
- Synthetic Biology and Bioprocessing Group, Regional Centre for Biotechnology, NCR-Biotech Cluster, Faridabad, India
| | - Sathish Dorairaj
- Synthetic Biology and Bioprocessing Group, Regional Centre for Biotechnology, NCR-Biotech Cluster, Faridabad, India
| | - Nidhi Adlakha
- Synthetic Biology and Bioprocessing Group, Regional Centre for Biotechnology, NCR-Biotech Cluster, Faridabad, India.
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Arai T, Ichinose S, Shibata N, Kakeshita H, Kodama H, Igarashi K, Takimura Y. Inducer-free cellulase production system based on the constitutive expression of mutated XYR1 and ACE3 in the industrial fungus Trichoderma reesei. Sci Rep 2022; 12:19445. [PMID: 36376415 PMCID: PMC9663580 DOI: 10.1038/s41598-022-23815-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2022] [Accepted: 11/07/2022] [Indexed: 11/16/2022] Open
Abstract
Trichoderma reesei is a widely used host for producing cellulase and hemicellulase cocktails for lignocellulosic biomass degradation. Here, we report a genetic modification strategy for industrial T. reesei that enables enzyme production using simple glucose without inducers, such as cellulose, lactose and sophorose. Previously, the mutated XYR1V821F or XYR1A824V was known to induce xylanase and cellulase using only glucose as a carbon source, but its enzyme composition was biased toward xylanases, and its performance was insufficient to degrade lignocellulose efficiently. Therefore, we examined combinations of mutated XYR1V821F and constitutively expressed CRT1, BGLR, VIB1, ACE2, or ACE3, known as cellulase regulators and essential factors for cellulase expression to the T. reesei E1AB1 strain that has been highly mutagenized for improving enzyme productivity and expressing a ß-glucosidase for high enzyme performance. The results showed that expression of ACE3 to the mutated XYR1V821F expressing strain promoted cellulase expression. Furthermore, co-expression of these two transcription factors also resulted in increased productivity, with enzyme productivity 1.5-fold higher than with the conventional single expression of mutated XYR1V821F. Additionally, that productivity was 5.5-fold higher compared to productivity with an enhanced single expression of ACE3. Moreover, although the DNA-binding domain of ACE3 had been considered essential for inducer-free cellulase production, we found that ACE3 with a partially truncated DNA-binding domain was more effective in cellulase production when co-expressed with a mutated XYR1V821F. This study demonstrates that co-expression of the two transcription factors, the mutated XYR1V821F or XYR1A824V and ACE3, resulted in optimized enzyme composition and increased productivity.
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Affiliation(s)
- Toshiharu Arai
- Biological Science Research, Kao Corporation, 1334 Minato, Wakayama, Wakayama, 640‑8580, Japan
| | - Sakurako Ichinose
- Biological Science Research, Kao Corporation, 1334 Minato, Wakayama, Wakayama, 640‑8580, Japan
| | - Nozomu Shibata
- Biological Science Research, Kao Corporation, 1334 Minato, Wakayama, Wakayama, 640‑8580, Japan
| | - Hiroshi Kakeshita
- Biological Science Research, Kao Corporation, 1334 Minato, Wakayama, Wakayama, 640‑8580, Japan.
| | - Hiroshi Kodama
- Biological Science Research, Kao Corporation, 1334 Minato, Wakayama, Wakayama, 640‑8580, Japan
| | - Kazuaki Igarashi
- Biological Science Research, Kao Corporation, 1334 Minato, Wakayama, Wakayama, 640‑8580, Japan
| | - Yasushi Takimura
- Biological Science Research, Kao Corporation, 1334 Minato, Wakayama, Wakayama, 640‑8580, Japan
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Identification of a Bidirectional Promoter from Trichoderma reesei and Its Application in Dual Gene Expression. J Fungi (Basel) 2022; 8:jof8101059. [PMID: 36294624 PMCID: PMC9604776 DOI: 10.3390/jof8101059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2022] [Revised: 10/03/2022] [Accepted: 10/08/2022] [Indexed: 11/17/2022] Open
Abstract
The cellulolytic filamentous fungus Trichoderma reesei has a strong capability in protein synthesis and secretion and is increasingly used as a fungal chassis for the production of heterologous proteins or secondary metabolites. However, bidirectional promoters that would significantly facilitate multiple genes’ expression have not been characterized in T. reesei. Herein, we show that a 767-bp intergenic region between two polyketide synthase encoding genes that were involved in the biosynthesis of the typical yellow pigment served as a bidirectional promoter in T. reesei. This region was shown to be able to drive the simultaneous expression of two fluorescence reporter genes when fused to each end. Quantitative RT-PCR analysis demonstrated that the driving strength of this bidirectional promoter from each direction reached about half of that of the commonly used promoter PgpdA. Moreover, the co-expression of two cellulase genes driven by this bidirectional promoter enabled T. reesei to produce cellulases on glucose and improved the total cellulase activities with cellulose Avicel as the carbon source. Our work identified the first bidirectional promoter in T. reesei, which would facilitate gene co-expression and find applications in synthetic biology using fungal systems.
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Zhang P, Li Q, Chen Y, Peng N, Liu W, Wang X, Li Y. Induction of cellulase production in Trichoderma reesei by a glucose-sophorose mixture as an inducer prepared using stevioside. RSC Adv 2022; 12:17392-17400. [PMID: 35765440 PMCID: PMC9190947 DOI: 10.1039/d2ra01192a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2022] [Accepted: 06/03/2022] [Indexed: 11/28/2022] Open
Abstract
Sophorose is currently the most effective inducer of cellulase production by Trichoderma reesei; however, the use of byproduct sophorose from the stevioside acid hydrolysis process has not been developed. In this study, stevioside was hydrolysed with different concentrations of HCl to obtain isosteviol and a mixture of glucose and sophorose (MGS). Isosteviol showed good inhibitory effects on the growth of Aspergillus niger, Saccharomyces cerevisiae and Escherichia coli after separation. At the same time, MGS, as a byproduct, was evaluated for cellulase production to determine the feasibility of this approach. MGS was compared with common soluble inducers, such as lactose, cellobiose, and a mixture of glucose and β-disaccharide (MGD), and induced higher cellulase production than the other inducers. The cellulase activity induced by MGS was 1.64- and 5.26-fold higher than that induced by lactose and cellobiose, respectively, and was not significantly different from that induced by MGD. The crude enzyme using MGS as an inducer with commercial β-glucosidase was further tested by hydrolyzing NaOH-pretreated corn stover with 5% solid loading, and 33.4 g L-1 glucose was released with a glucose yield of 96.04%. The strategy developed in this work will be beneficial for reducing inducer production cost through a simple stevia glycoside hydrolysis reaction and will contribute to studies aimed at improving cellulase production using soluble inducers for easier operation in industrial-scale cellulase production.
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Affiliation(s)
- Peng Zhang
- Chongqing Key Laboratory of Industrial Fermentation Microorganism, School of Chemistry and Chemical Engineering, Chongqing University of Science and Technology Chongqing 401331 China +86-23-65022211
| | - Qian Li
- Chongqing Key Laboratory of Industrial Fermentation Microorganism, School of Chemistry and Chemical Engineering, Chongqing University of Science and Technology Chongqing 401331 China +86-23-65022211
| | - Yudian Chen
- Chongqing Key Laboratory of Industrial Fermentation Microorganism, School of Chemistry and Chemical Engineering, Chongqing University of Science and Technology Chongqing 401331 China +86-23-65022211
| | - Nian Peng
- Chongqing Key Laboratory of Industrial Fermentation Microorganism, School of Chemistry and Chemical Engineering, Chongqing University of Science and Technology Chongqing 401331 China +86-23-65022211
| | - Wenshu Liu
- Chongqing Key Laboratory of Industrial Fermentation Microorganism, School of Chemistry and Chemical Engineering, Chongqing University of Science and Technology Chongqing 401331 China +86-23-65022211
| | - Xuemei Wang
- Chongqing Key Laboratory of Industrial Fermentation Microorganism, School of Chemistry and Chemical Engineering, Chongqing University of Science and Technology Chongqing 401331 China +86-23-65022211
| | - Yonghao Li
- Chongqing Key Laboratory of Industrial Fermentation Microorganism, School of Chemistry and Chemical Engineering, Chongqing University of Science and Technology Chongqing 401331 China +86-23-65022211
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Acetate derivative of Morita –Baylis-Hillman adducts (MBH): a powerful antifungal. Saudi J Biol Sci 2022. [DOI: 10.1016/j.sjbs.2022.103343] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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11
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Regulation of β-Disaccharide Accumulation by β-Glucosidase Inhibitors to Enhance Cellulase Production in Trichoderma reesei. FERMENTATION-BASEL 2022. [DOI: 10.3390/fermentation8050232] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Trichoderma reesei is a high-yield producer of cellulase for applications in lignocellulosic biomass conversion, but its cellulase production requires induction. A mixture of glucose and β-disaccharide has been demonstrated to achieve high-level cellulase production. However, as inducers, β-disaccharides are prone to be hydrolyzed by β-glucosidase (BGL) during fermentation, therefore β-disaccharides need to be supplemented through feeding to overcome this problem. Here, miglitol, an α-glucosidase inhibitor, was investigated as a BGL inhibitor, and exhibited an IC50 value of 2.93 μg/mL. The cellulase titer was more than two-fold when miglitol was added to the fermentation medium of T. reesei. This method was similar to the prokaryotic expression system using unmetabolized isopropyl-β-D-thiogalactopyranoside (IPTG) as the inducer instead of lactose to continuously induce gene expression. However, cellulase activity was not enhanced with BGL inhibition when lactose or cellulose was used as an inducer, which demonstrated that the transglycosidase activity of BGL is important for the inducible activity of lactose and cellulose. This novel method demonstrates potential in stimulating cellulase production and provides a promising system for T. reesei protein expression.
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12
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Xu W, Fang Y, Ding M, Ren Y, Meng X, Chen G, Zhang W, Liu W. Elimination of the Sugar Transporter GAT1 Increased Xylanase I Production in Trichoderma reesei. Front Microbiol 2022; 13:810066. [PMID: 35154055 PMCID: PMC8825865 DOI: 10.3389/fmicb.2022.810066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Accepted: 01/04/2022] [Indexed: 11/17/2022] Open
Abstract
The filamentous fungus Trichoderma reesei secretes large quantities of cellulases and hemicellulases that have found wide applications in industry. Compared with extensive studies on the mechanism controlling cellulase gene expression, less is known about the regulatory mechanism behind xylanase gene expression. Herein, several putative sugar transporter encoding genes that showed significant upregulation on xylan were identified in T. reesei. Deletion of one such gene, gat1, resulted in increased xylanase production but hardly affected cellulase induction. Further analyses demonstrated that deletion of gat1 markedly increased XYNI production at the transcriptional level and only exerted a minor effect on XYNII synthesis. In contrast, overexpressing gat1 caused a continuous decrease in xyn1 expression. Deletion of gat1 also affected the expression of xyn1 and pectinase genes when T. reesei was cultivated with galacturonic acid as the sole carbon source. Transcriptome analyses of Δgat1 and its parental strain identified 255 differentially expressed genes that are enriched in categories of glycoside hydrolases, lipid metabolism, transporters, and transcriptional factors. The results thus implicate a repressive role of the sugar transporter GAT1 in xyn1 expression and reveal that distinct regulatory mechanisms may exist in controlling the expression of different xylanase genes in T. reesei.
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Affiliation(s)
- Wenqiang Xu
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China
| | - Yu Fang
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China
| | - Mingyang Ding
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China
| | - Yajing Ren
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China
| | - Xiangfeng Meng
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China
| | - Guanjun Chen
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China
| | - Weixin Zhang
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China
| | - Weifeng Liu
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China
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13
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Li Y, Zhang P, Zhu D, Yao B, Hasunuma T, Kondo A, Zhao X. Efficient preparation of soluble inducer for cellulase production and saccharification of corn stover using in-house generated crude enzymes. Biochem Eng J 2022. [DOI: 10.1016/j.bej.2021.108296] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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14
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15
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Imran M, Abulreesh HH, Monjed MK, Elbanna K, Samreen, Ahmad I. Multifarious functional traits of free-living rhizospheric fungi, with special reference to Aspergillus spp. isolated from North Indian soil, and their inoculation effect on plant growth. ANN MICROBIOL 2021. [DOI: 10.1186/s13213-021-01643-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Abstract
Purpose
Rhizospheric soil fungi are critical for plant and soil health. However, their multiple functional traits and impact on plant growth have not been systematically explored.
Methods
During this study, biochemical traits of 73 indigenous soil fungal isolates and 15 unidentified isolates related to plant growth promotion and production of extracellular enzymes were studied.
Results
Forty four (65.67%) of the total isolates produced indole acetic acid (IAA) followed by siderophore (52.23%), phosphate solubilization (37.31%), and antibiotic (11.93%). 91.04% of the studied isolates produced ammonia whereas 28.35% produced organic acid. Extracellular enzyme activities of lipase, amylase, chitinase, and cellulase were detected among 95.52%, 61.11%, 35.82%, and 41.79% isolates, respectively. Based on these activities, 73 fungal isolates were categorized into different biotypes. Quantitative analysis of IAA production and phosphate solubilization was carried out for Aspergillus, Penicillium, and Rhizopus isolates. Aspergillus isolates exhibited varying activities of IAA production and phosphate solubilization. Most of the Aspergillus isolates and some other fungi demonstrated multiple activities. Based on the multiple traits of selected fungal isolates, Aspergillus sp-07, Penicillium sp-03, and Rhizopus sp-02 were further evaluated in different combinations for their inoculation effect on the growth and yield of wheat under field conditions.
Conclusions
The results indicated that these isolates could be developed into bio-inoculants to enhance plant growth. The consortium of these three isolates was also found to be compatible and beneficial for plant growth.
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16
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Najjarzadeh N, Matsakas L, Rova U, Christakopoulos P. How Carbon Source and Degree of Oligosaccharide Polymerization Affect Production of Cellulase-Degrading Enzymes by Fusarium oxysporum f. sp. lycopersici. Front Microbiol 2021; 12:652655. [PMID: 33841380 PMCID: PMC8032549 DOI: 10.3389/fmicb.2021.652655] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Accepted: 02/22/2021] [Indexed: 11/13/2022] Open
Abstract
Cellulases are a group of enzymes responsible for the degradation of cellulose, which is one of the most abundant polymers on Earth. The three main groups of cellulases are endoglucosidases, exoglucosidases, and β-glucosidases; however, the mechanism of induction of these enzymes remains poorly characterized. Cellooligosaccharides are among the main inducers of these enzymes in filamentous fungi, yet it is not clear how their degree of polymerization may affect the strength of induction. In the present study, we investigated the effect of different carbohydrate-based inducers, such as lactose, sophorose, cellooligosaccharides, and xylooligosacharides, characterized by different concentrations and degree of polymerization, on cellulases production by the fungus Fusarium oxysporum f. sp. lycopersici, which is one of the most studied lignocellulose degrading fungi with the ability to consume both cellulose and hemicellulose. Moreover, the effect of carbon source on cellulase induction was assessed by growing the biomass on sucrose or glycerol. Results showed a correlation between induction efficiency and the cellooligosaccharides' concentration and size, as well as the carbon source available. Specifically, cellotetraose was a better inducer when sucrose was the carbon source, while cellobiose yielded a better result on glycerol. These findings can help optimize industrial cellulase production.
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Affiliation(s)
| | | | | | - Paul Christakopoulos
- Biochemical Process Engineering, Division of Chemical Engineering, Department of Civil, Environmental and Natural Resources Engineering, Luleå University of Technology, Luleå, Sweden
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17
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Luo Y, Valkonen M, Jackson RE, Palmer JM, Bhalla A, Nikolaev I, Saloheimo M, Ward M. Modification of transcriptional factor ACE3 enhances protein production in Trichoderma reesei in the absence of cellulase gene inducer. BIOTECHNOLOGY FOR BIOFUELS 2020; 13:137. [PMID: 32782473 PMCID: PMC7412840 DOI: 10.1186/s13068-020-01778-w] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Accepted: 07/29/2020] [Indexed: 05/31/2023]
Abstract
BACKGROUND Trichoderma reesei is one of the best-known cellulolytic organisms, producing large quantities of a complete set of extracellular cellulases and hemicellulases for the degradation of lignocellulosic substances. Hence, T. reesei is a biotechnically important host and it is used commercially in enzyme production, of both native and foreign origin. Many strategies for producing enzymes in T. reesei rely on the cbh1 and other cellulase gene promoters for high-level expression and these promoters require induction by sophorose, lactose or other inducers for high productivity during manufacturing. RESULTS We described an approach for producing high levels of secreted proteins by overexpression of a transcription factor ACE3 in T. reesei. We refined the ace3 gene structure and identified specific ACE3 variants that enable production of secreted cellulases and hemicellulases on glucose as a sole carbon source (i.e., in the absence of an inducer). These specific ACE3 variants contain a full-length Zn2Cys6 binuclear cluster domain at the N-terminus and a defined length of truncations at the C-terminus. When expressed at a moderate level in the fungal cells, the ACE3 variants can induce high-level expression of cellulases and hemicellulases on glucose (i.e., in the absence of an inducer), and further improve expression on lactose or glucose/sophorose (i.e., in the presence of an inducer). Finally, we demonstrated that this method is applicable to industrial strains and fermentation conditions, improving protein production both in the absence and in the presence of an inducer. CONCLUSIONS This study demonstrates that overexpression of ACE3 variants enables a high level of protein production in the absence of an inducer, and boosts protein production in the presence of an inducer. It is an efficient approach to increase protein productivity and to reduce manufacturing costs.
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Affiliation(s)
- Yun Luo
- DuPont Industrial Biosciences, Genencor Research Center, 925 Page Mill Road, Palo Alto, CA 94304 USA
| | - Mari Valkonen
- VTT Technical Research Centre of Finland Ltd, P.O. Box 1000, FI-02044 VTT Espoo, Finland
| | - Raymond E. Jackson
- DuPont Experimental Station, 200 Powder Mill Road, Wilmington, DE 19803 USA
| | - Jonathan M. Palmer
- DuPont Industrial Biosciences, Genencor Research Center, 925 Page Mill Road, Palo Alto, CA 94304 USA
| | - Aditya Bhalla
- DuPont Industrial Biosciences, Genencor Research Center, 925 Page Mill Road, Palo Alto, CA 94304 USA
| | - Igor Nikolaev
- DuPont Industrial Biosciences, Genencor B.V., Willem Einthovenstraat 4, 2342 BH Oegstgeest, The Netherlands
| | - Markku Saloheimo
- VTT Technical Research Centre of Finland Ltd, P.O. Box 1000, FI-02044 VTT Espoo, Finland
| | - Michael Ward
- DuPont Industrial Biosciences, Genencor Research Center, 925 Page Mill Road, Palo Alto, CA 94304 USA
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18
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Okal EJ, Aslam MM, Karanja JK, Nyimbo WJ. Mini review: Advances in understanding regulation of cellulase enzyme in white-rot basidiomycetes. Microb Pathog 2020; 147:104410. [PMID: 32707312 DOI: 10.1016/j.micpath.2020.104410] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Revised: 07/14/2020] [Accepted: 07/17/2020] [Indexed: 12/17/2022]
Abstract
White-rot basidiomycetic fungi have gained a lot of scientific attention in recent years owing to their ability to produce cellulase enzymes that are of great importance in numerous industrial applications. This has seen a rise in number of studies seeking to comprehend both physical and molecular mechanisms that regulate the production of cellulase enzymes in these fungi. Cellulase has several applications in production of food and beverages, biofuel, biological detergents, pharmaceuticals, and deinking in paper and pulp industry. Enhanced understanding of genetic mechanisms that regulate cellulase production would have utility for optimal cellulase production in white-rot basidiomycetes using biotechnology approaches. Carbon catabolite repression and various transcriptional factors such as XlnR, Cre, Clr, Ace, and gna1 control expression of genes encoding cellobiohydrolase (CBH), endoglucanase (EGL) and β-glucosidase (BGL). In this review, we have consolidated and summarised some of recent findings on genetic regulation of cellulase with an aim of highlighting the general regulatory mechanisms that underlie cellulase expressions in white-rot fungi. This review further outlines some of important transcription factors that regulate cellulase genes, and key research gaps that may need to be addressed by future research.
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Affiliation(s)
- Eyalira J Okal
- Juncao Research Center, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, Fujian, 350002, China.
| | - Mehtab Muhammad Aslam
- Center for Plant Water-Use and Nutrition Regulation, College of Life Sciences, Joint International Research Laboratory of Water and Nutrient in Cops, Fujian Agriculture and Forestry University, Fuzhou, Fujian, 350002, China
| | - Joseph K Karanja
- Center for Plant Water-Use and Nutrition Regulation, College of Life Sciences, Joint International Research Laboratory of Water and Nutrient in Cops, Fujian Agriculture and Forestry University, Fuzhou, Fujian, 350002, China
| | - Witness J Nyimbo
- Juncao Research Center, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, Fujian, 350002, China
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19
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Janežič D, Jäntschi L, Bolboacă SD. Sugars and Sweeteners: Structure, Properties and In Silico Modeling. Curr Med Chem 2020; 27:5-22. [PMID: 30259809 DOI: 10.2174/0929867325666180926144401] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2016] [Revised: 01/15/2018] [Accepted: 03/09/2018] [Indexed: 11/22/2022]
Abstract
Several studies report the effects of excessive use of sugars and sweeteners in the diet. These include obesity, cardiac diseases, diabetes, and even lymphomas, leukemias, cancers of the bladder and brain, chronic fatigue syndrome, Parkinson's disease, Alzheimer's disease, multiple sclerosis, autism, and systemic lupus. On the other hand, each sugar and sweetener has a distinct metabolic assimilation process, and its chemical structure plays an important role in this process. Several scientific papers present the biological effects of the sugars and sweeteners in relation to their chemical structure. One important issue dealing with the sugars is the degree of similarity in their structures, focusing mostly on optical isomerism. Finding and developing new sugars and sweeteners with desired properties is an emerging research area, in which in silico approaches play an important role.
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Affiliation(s)
- Dušanka Janežič
- Faculty of Mathematics, Natural Sciences and Information Technologies, University of Primorska, Koper, Slovenia
| | - Lorentz Jäntschi
- Department of Physics and Chemistry, Technical University of Cluj-Napoca, Cluj-Napoca, Romania.,Chemistry Doctoral School, Babeş-Bolyai University, Cluj-Napoca, Romania
| | - Sorana D Bolboacă
- Department of Medical Informatics and Biostatistics, Iuliu Haţieganu University of Medicine and Pharmacy, Cluj-Napoca, Romania
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20
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Genetically Modified Microbes for Second-Generation Bioethanol Production. Fungal Biol 2020. [DOI: 10.1007/978-3-030-41870-0_7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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21
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Crosstalk of Cellulose and Mannan Perception Pathways Leads to Inhibition of Cellulase Production in Several Filamentous Fungi. mBio 2019; 10:mBio.00277-19. [PMID: 31266859 PMCID: PMC6606794 DOI: 10.1128/mbio.00277-19] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In fungi, the production of enzymes for polysaccharide degradation is controlled by complex signaling networks. Previously, these networks were studied in response to simple sugars or single polysaccharides. Here, we tackled for the first time the molecular interplay between two seemingly unrelated perception pathways: those for cellulose and the hemicellulose (gluco)mannan. We identified a so far unknown competitive inhibition between the respective degradation products acting as signaling molecules. Competition was detected both at the level of the uptake and intracellularly, upstream of the main transcriptional regulator CLR-2. Our findings provide novel insights into the molecular communication between perception pathways. Also, they present possible targets for the improvement of industrial strains for higher cellulase production through the engineering of mannan insensitivity. It is essential for microbes to acquire information about their environment. Fungi use soluble degradation products of plant cell wall components to understand the substrate composition they grow on. Individual perception pathways have been well described. However, the interconnections between pathways remain poorly understood. In the present work, we provide evidence of crosstalk between the perception pathways for cellulose and the hemicellulose mannan being conserved in several filamentous fungi and leading to the inhibition of cellulase expression. We used the functional genomics tools available for Neurospora crassa to investigate this overlap at the molecular level. Crosstalk and competitive inhibition could be identified both during uptake by cellodextrin transporters and intracellularly. Importantly, the overlap is independent of CRE-1-mediated catabolite repression. These results provide novel insights into the regulatory networks of lignocellulolytic fungi and will contribute to the rational optimization of fungal enzyme production for efficient plant biomass depolymerization and utilization.
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22
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Daranagama ND, Shioya K, Yuki M, Sato H, Ohtaki Y, Suzuki Y, Shida Y, Ogasawara W. Proteolytic analysis of Trichoderma reesei in celluase-inducing condition reveals a role for trichodermapepsin (TrAsP) in cellulase production. ACTA ACUST UNITED AC 2019; 46:831-842. [DOI: 10.1007/s10295-019-02155-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2018] [Accepted: 02/12/2019] [Indexed: 12/22/2022]
Abstract
Abstract
Filamentous fungi produce a variety of proteases with significant biotechnological potential and show diverse substrate specificities. Proteolytic analysis of the industrial enzyme producer Trichoderma reesei has been sparse. Therefore, we determined the substrate specificity of T. reesei secretome and its main protease Trichodermapepsin (TrAsP) up to P1 position using FRETS-25Xaa-libraries. The role of TrAsP was analyzed using T. reesei QM9414 and the deletant QM∆trasp in Avicel. We observed higher activities of CMCase, Avicelase, and Xylanase in QM∆t rasp compared to that of QM9414. Saccharification rate of cellulosic biomass also increased when using secretome of QM∆trasp but the effect was not significant due to the absence of difference in BGL activity compared to QM9414. Higher TrAsP was produced when monosaccharides were used as a carbon source compared to cellulase inducers such as Avicel and α-sophorose. These results elucidate the relationship between TrAsP and cellulase production in T. reesei and suggest a physiological role for TrAsP.
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Affiliation(s)
- Nayani Dhanushka Daranagama
- 0000 0001 0671 2234 grid.260427.5 Department of Bioengineering Nagaoka University of Technology 1603-1, Kamitomioka 940-2188 Nagaoka Japan
| | - Koki Shioya
- 0000 0001 0671 2234 grid.260427.5 Department of Bioengineering Nagaoka University of Technology 1603-1, Kamitomioka 940-2188 Nagaoka Japan
| | - Masahiro Yuki
- 0000 0001 0671 2234 grid.260427.5 Department of Bioengineering Nagaoka University of Technology 1603-1, Kamitomioka 940-2188 Nagaoka Japan
| | - Haruna Sato
- 0000 0001 0671 2234 grid.260427.5 Department of Bioengineering Nagaoka University of Technology 1603-1, Kamitomioka 940-2188 Nagaoka Japan
| | - Yuki Ohtaki
- 0000 0001 0671 2234 grid.260427.5 Department of Bioengineering Nagaoka University of Technology 1603-1, Kamitomioka 940-2188 Nagaoka Japan
| | - Yoshiyuki Suzuki
- 0000 0001 0671 2234 grid.260427.5 Department of Bioengineering Nagaoka University of Technology 1603-1, Kamitomioka 940-2188 Nagaoka Japan
| | - Yosuke Shida
- 0000 0001 0671 2234 grid.260427.5 Department of Bioengineering Nagaoka University of Technology 1603-1, Kamitomioka 940-2188 Nagaoka Japan
| | - Wataru Ogasawara
- 0000 0001 0671 2234 grid.260427.5 Department of Bioengineering Nagaoka University of Technology 1603-1, Kamitomioka 940-2188 Nagaoka Japan
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Patel AK, Singhania RR, Sim SJ, Pandey A. Thermostable cellulases: Current status and perspectives. BIORESOURCE TECHNOLOGY 2019; 279:385-392. [PMID: 30685132 DOI: 10.1016/j.biortech.2019.01.049] [Citation(s) in RCA: 110] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Revised: 01/09/2019] [Accepted: 01/11/2019] [Indexed: 05/18/2023]
Abstract
It is envisaged that the utilization of lignocellulosic biomass for ethanol production for transport sector, would make cellulases the most demanded industrial enzyme. The greatest potential of cellulolytic enzymes lies in ethanol production from biomass by enzymatic hydrolysis of cellulose but low thermostability and low titer of cellulase production resulting into high cost of the enzyme which is the major set-back. A number of research groups are working on cellulase to improve its thermostability so as to be able to perform hydrolysis at elevated temperatures which would eventually increase the efficiency of cellulose hydrolysis. The technologies developed from lignocellulosic biomass via cellulose hydrolysis promise environmental and economical sustainability in the long run along with non-dependence on nonrenewable energy source. This review deals with the important sources of thermostable cellulases, mechanism, its regulation, strategies to enhance the thermostability further with respect to its importance for biofuel applications.
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Affiliation(s)
- Anil K Patel
- Department of Chemical and Biological Engineering, Korea University, Seoul 02841, Republic of Korea
| | | | - Sang Jun Sim
- Department of Chemical and Biological Engineering, Korea University, Seoul 02841, Republic of Korea
| | - Ashok Pandey
- Centre for Innovation and Translational Research, Indian Institute of Toxicological Research, Lucknow 226 001, India
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24
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Chen Y, Wu C, Shen Y, Ma Y, Wei D, Wang W. N, N-dimethylformamide induces cellulase production in the filamentous fungus Trichoderma reesei. BIOTECHNOLOGY FOR BIOFUELS 2019; 12:36. [PMID: 30820246 PMCID: PMC6380019 DOI: 10.1186/s13068-019-1375-1] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2018] [Accepted: 02/08/2019] [Indexed: 05/04/2023]
Abstract
BACKGROUND The filamentous fungus Trichoderma reesei produces cellulase enzymes that are widely studied for lignocellulose bioconversion to biofuel. N,N-dimethylformamide (DMF) is a versatile organic solvent used in large quantities in industries. RESULTS In this study, we serendipitously found that biologically relevant concentrations of extracellular DMF-induced cellulase production in the T. reesei hyper-cellulolytic mutant Rut-C30 and wild-type strain QM6a. Next, by transcriptome analysis, we determined that plc-e encoding phospholipase C was activated by DMF and revealed that cytosolic Ca2+ plays a vital role in the response of T. reesei to DMF. Using EGTA (a putative extracellular Ca2+ chelator) and LaCl3 (a plasma membrane Ca2+ channel blocker), we demonstrated that DMF induced a cytosolic Ca2+ burst via extracellular Ca2+ and Ca2+ channels in T. reesei, and that the cytosolic Ca2+ burst induced by DMF-mediated overexpression of cellulase through calcium signaling. Deletion of crz1 confirmed that calcium signaling plays a dominant role in DMF-induced cellulase production. Additionally, 0.5-2% DMF increases the permeability of T. reesei mycelia for cellulase release. Simultaneous supplementation with 1% DMF and 10 mM Mn2+ to T. reesei Rut-C30 increased cellulase activity approximately fourfold compared to that without treatment and was also more than that observed in response to either treatment alone. CONCLUSIONS Our results reveal that DMF-induced cellulase production via calcium signaling and permeabilization. Our results also provide insight into the role of calcium signaling in enzyme production for enhanced cellulase production and the development of novel inducers of cellulase.
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Affiliation(s)
- Yumeng Chen
- State Key Lab of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, P.O.B. 311, Shanghai, 200237 China
| | - Chuan Wu
- State Key Lab of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, P.O.B. 311, Shanghai, 200237 China
| | - Yaling Shen
- State Key Lab of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, P.O.B. 311, Shanghai, 200237 China
| | - Yushu Ma
- State Key Lab of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, P.O.B. 311, Shanghai, 200237 China
| | - Dongzhi Wei
- State Key Lab of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, P.O.B. 311, Shanghai, 200237 China
| | - Wei Wang
- State Key Lab of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, P.O.B. 311, Shanghai, 200237 China
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25
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Fitz E, Wanka F, Seiboth B. The Promoter Toolbox for Recombinant Gene Expression in Trichoderma reesei. Front Bioeng Biotechnol 2018; 6:135. [PMID: 30364340 PMCID: PMC6193071 DOI: 10.3389/fbioe.2018.00135] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2018] [Accepted: 09/12/2018] [Indexed: 01/05/2023] Open
Abstract
The ascomycete Trichoderma reesei is one of the main fungal producers of cellulases and xylanases based on its high production capacity. Its enzymes are applied in food, feed, and textile industry or in lignocellulose hydrolysis in biofuel and biorefinery industry. Over the last years, the demand to expand the molecular toolbox for T. reesei to facilitate genetic engineering and improve the production of heterologous proteins grew. An important instrument to modify the expression of key genes are promoters to initiate and control their transcription. To date, the most commonly used promoter for T. reesei is the strong inducible promoter of the main cellobiohydrolase cel7a. Beside this one, there is a number of alternative inducible promoters derived from other cellulase- and xylanase encoding genes and a few constitutive promoters. With the advances in genomics and transcriptomics the identification of new constitutive and tunable promoters with different expression strength was simplified. In this review, we will discuss new developments in the field of promoters and compare their advantages and disadvantages. Synthetic expression systems constitute a new option to control gene expression and build up complex gene circuits. Therefore, we will address common structural features of promoters and describe options for promoter engineering and synthetic design of promoters. The availability of well-characterized gene expression control tools is essential for the analysis of gene function, detection of bottlenecks in gene networks and yield increase for biotechnology applications.
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Affiliation(s)
- Elisabeth Fitz
- Research Division Biochemical Technology, Institute of Chemical, Environmental and Bioscience Engineering, TU Wien, Vienna, Austria.,Austrian Centre of Industrial Biotechnology (ACIB) GmbH, Institute of Chemical, Environmental and Bioscience Engineering, TU Wien, Vienna, Austria
| | - Franziska Wanka
- Austrian Centre of Industrial Biotechnology (ACIB) GmbH, Institute of Chemical, Environmental and Bioscience Engineering, TU Wien, Vienna, Austria
| | - Bernhard Seiboth
- Research Division Biochemical Technology, Institute of Chemical, Environmental and Bioscience Engineering, TU Wien, Vienna, Austria.,Austrian Centre of Industrial Biotechnology (ACIB) GmbH, Institute of Chemical, Environmental and Bioscience Engineering, TU Wien, Vienna, Austria
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26
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Tanaka N, Nakajima M, Aramasa H, Nakai H, Taguchi H, Tsuzuki W, Komba S. Synthesis of three deoxy-sophorose derivatives for evaluating the requirement of hydroxy groups at position 3 and/or 3' of sophorose by 1,2-β-oligoglucan phosphorylases. Carbohydr Res 2018; 468:13-22. [PMID: 30121414 DOI: 10.1016/j.carres.2018.08.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2018] [Revised: 08/09/2018] [Accepted: 08/09/2018] [Indexed: 10/28/2022]
Abstract
Sophorose (Sop2) is known as a powerful inducer of cellulases in Trichoderma reesei, and in recent years 1,2-β-D-oligoglucan phosphorylase (SOGP) has been found to use Sop2 in synthetic reactions. From the structure of the complex of SOGP with Sop2, it was predicted that both the 3-hydroxy group at the reducing end glucose moiety of Sop2 and the 3'-hydroxy group at the non-reducing end glucose moiety of Sop2 were important for substrate recognition. In this study, three kinds of 3- and/or 3'-deoxy-Sop2 derivatives were synthesized to evaluate this mechanism. The deoxygenation of the 3-hydroxy group of D-glucopyranose derivative was performed by radical reduction using a toluoyl group as a leaving group. The utilization of a toluoyl group that plays two roles (a leaving group for the deoxygenation and a protecting group for a hydroxy group) resulted in efficient syntheses of the three target compounds. The NMR spectra of the two final compounds (3-deoxy- and 3,3'-dideoxy-Sop2) suggested that the glucose moiety of the reducing end of Sop2 can easily take on a furanose structure (five-membered ring structure) by deoxygenation of the 3-hydroxy group of Sop2. In addition, the ratio of the five- and six-membered ring structures changed depending on the temperature. The SOGPs exhibited remarkably lower specific activity for 3'-deoxy- and 3,3'-dideoxy-Sop2, indicating that the 3'-hydroxy group of Sop2 is important for substrate recognition by SOGPs.
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Affiliation(s)
- Nobukiyo Tanaka
- Department of Applied Biological Science, Faculty of Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278-8510, Japan; Food Component Analysis Unit, Food Research Institute, National Agriculture and Food Research Organization, 2-1-12, Kannondai, Tsukuba, Ibaraki 305-8642, Japan
| | - Masahiro Nakajima
- Department of Applied Biological Science, Faculty of Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278-8510, Japan
| | - Hiroki Aramasa
- Faculty of Agriculture, Niigata University, Niigata 950-2181, Japan
| | - Hiroyuki Nakai
- Faculty of Agriculture, Niigata University, Niigata 950-2181, Japan
| | - Hayao Taguchi
- Department of Applied Biological Science, Faculty of Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278-8510, Japan
| | - Wakako Tsuzuki
- Food Component Analysis Unit, Food Research Institute, National Agriculture and Food Research Organization, 2-1-12, Kannondai, Tsukuba, Ibaraki 305-8642, Japan
| | - Shiro Komba
- Food Component Analysis Unit, Food Research Institute, National Agriculture and Food Research Organization, 2-1-12, Kannondai, Tsukuba, Ibaraki 305-8642, Japan.
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Xia Y, Yang L, Xia L. Preparation of a novel soluble inducer by cellobiase-release microcapsules and its application in cellulase production. J Biotechnol 2018; 279:22-26. [DOI: 10.1016/j.jbiotec.2018.05.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2017] [Revised: 04/03/2018] [Accepted: 05/02/2018] [Indexed: 01/05/2023]
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Xia Y, Yang L, Xia L. High-level production of a fungal β-glucosidase with application potentials in the cost-effective production of Trichoderma reesei cellulase. Process Biochem 2018. [DOI: 10.1016/j.procbio.2018.03.031] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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Abe K, Sunagawa N, Terada T, Takahashi Y, Arakawa T, Igarashi K, Samejima M, Nakai H, Taguchi H, Nakajima M, Fushinobu S. Structural and thermodynamic insights into β-1,2-glucooligosaccharide capture by a solute-binding protein in Listeria innocua. J Biol Chem 2018; 293:8812-8828. [PMID: 29678880 DOI: 10.1074/jbc.ra117.001536] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Revised: 04/18/2018] [Indexed: 12/26/2022] Open
Abstract
β-1,2-Glucans are bacterial carbohydrates that exist in cyclic or linear forms and play an important role in infections and symbioses involving Gram-negative bacteria. Although several β-1,2-glucan-associated enzymes have been characterized, little is known about how β-1,2-glucan and its shorter oligosaccharides (Sop n s) are captured and imported into the bacterial cell. Here, we report the biochemical and structural characteristics of the Sop n -binding protein (SO-BP, Lin1841) associated with the ATP-binding cassette (ABC) transporter from the Gram-positive bacterium Listeria innocua Calorimetric analysis revealed that SO-BP specifically binds to Sop n s with a degree of polymerization of 3 or more, with Kd values in the micromolar range. The crystal structures of SO-BP in an unliganded open form and in closed complexes with tri-, tetra-, and pentaoligosaccharides (Sop3-5) were determined to a maximum resolution of 1.6 Å. The binding site displayed shape complementarity to Sop n , which adopted a zigzag conformation. We noted that water-mediated hydrogen bonds and stacking interactions play a pivotal role in the recognition of Sop3-5 by SO-BP, consistent with its binding thermodynamics. Computational free-energy calculations and a mutational analysis confirmed that interactions with the third glucose moiety of Sop n s are significantly responsible for ligand binding. A reduction in unfavorable changes in binding entropy that were in proportion to the lengths of the Sop n s was explained by conformational entropy changes. Phylogenetic and sequence analyses indicated that SO-BP ABC transporter homologs, glycoside hydrolases, and other related proteins are co-localized in the genomes of several bacteria. This study may improve our understanding of bacterial β-1,2-glucan metabolism and promote the discovery of unidentified β-1,2-glucan-associated proteins.
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Affiliation(s)
- Koichi Abe
- From the Department of Biotechnology.,Agricultural Bioinformatics Research Unit, and
| | - Naoki Sunagawa
- Department of Biomaterial Sciences, Graduate School of Agricultural and Life Sciences, University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | | | - Yuta Takahashi
- the Faculty of Agriculture, Niigata University, Niigata 950-2181, Japan
| | | | - Kiyohiko Igarashi
- Department of Biomaterial Sciences, Graduate School of Agricultural and Life Sciences, University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan.,the VTT Technical Research Centre of Finland, Espoo FI-02044 VTT, Finland, and
| | - Masahiro Samejima
- Department of Biomaterial Sciences, Graduate School of Agricultural and Life Sciences, University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Hiroyuki Nakai
- the Faculty of Agriculture, Niigata University, Niigata 950-2181, Japan
| | - Hayao Taguchi
- the Department of Applied Biological Science, Faculty of Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278-8510, Japan
| | - Masahiro Nakajima
- the Department of Applied Biological Science, Faculty of Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278-8510, Japan
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Production and spectroscopic characterization of lytic polysaccharide monooxygenases. Methods Enzymol 2018; 613:63-90. [DOI: 10.1016/bs.mie.2018.10.014] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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Massonnet M, Morales‐Cruz A, Figueroa‐Balderas R, Lawrence DP, Baumgartner K, Cantu D. Condition-dependent co-regulation of genomic clusters of virulence factors in the grapevine trunk pathogen Neofusicoccum parvum. MOLECULAR PLANT PATHOLOGY 2018; 19:21-34. [PMID: 27608421 PMCID: PMC6637977 DOI: 10.1111/mpp.12491] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/08/2016] [Revised: 09/01/2016] [Accepted: 09/02/2016] [Indexed: 05/24/2023]
Abstract
The ascomycete Neofusicoccum parvum, one of the causal agents of Botryosphaeria dieback, is a destructive wood-infecting fungus and a serious threat to grape production worldwide. The capability to colonize woody tissue, combined with the secretion of phytotoxic compounds, is thought to underlie its pathogenicity and virulence. Here, we describe the repertoire of virulence factors and their transcriptional dynamics as the fungus feeds on different substrates and colonizes the woody stem. We assembled and annotated a highly contiguous genome using single-molecule real-time DNA sequencing. Transcriptome profiling by RNA sequencing determined the genome-wide patterns of expression of virulence factors both in vitro (potato dextrose agar or medium amended with grape wood as substrate) and in planta. Pairwise statistical testing of differential expression, followed by co-expression network analysis, revealed that physically clustered genes coding for putative virulence functions were induced depending on the substrate or stage of plant infection. Co-expressed gene clusters were significantly enriched not only in genes associated with secondary metabolism, but also in those associated with cell wall degradation, suggesting that dynamic co-regulation of transcriptional networks contributes to multiple aspects of N. parvum virulence. In most of the co-expressed clusters, all genes shared at least a common motif in their promoter region, indicative of co-regulation by the same transcription factor. Co-expression analysis also identified chromatin regulators with correlated expression with inducible clusters of virulence factors, suggesting a complex, multi-layered regulation of the virulence repertoire of N. parvum.
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Affiliation(s)
- Mélanie Massonnet
- Department of Viticulture and EnologyUniversity of California DavisDavisCA95616USA
| | - Abraham Morales‐Cruz
- Department of Viticulture and EnologyUniversity of California DavisDavisCA95616USA
| | | | - Daniel P. Lawrence
- Department of Plant PathologyUniversity of California DavisDavisCA95616USA
| | - Kendra Baumgartner
- US Department of Agriculture ‐ Agricultural Research ServiceCrops Pathology and Genetics Research UnitDavisCA95616USA
| | - Dario Cantu
- Department of Viticulture and EnologyUniversity of California DavisDavisCA95616USA
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Gao J, Qian Y, Wang Y, Qu Y, Zhong Y. Production of the versatile cellulase for cellulose bioconversion and cellulase inducer synthesis by genetic improvement of Trichoderma reesei. BIOTECHNOLOGY FOR BIOFUELS 2017; 10:272. [PMID: 29167702 PMCID: PMC5688634 DOI: 10.1186/s13068-017-0963-1] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2017] [Accepted: 11/07/2017] [Indexed: 05/05/2023]
Abstract
BACKGROUND The enzymes for efficient hydrolysis of lignocellulosic biomass are a major factor in the development of an economically feasible cellulose bioconversion process. Up to now, low hydrolysis efficiency and high production cost of cellulases remain the significant hurdles in this process. The aim of the present study was to develop a versatile cellulase system with the enhanced hydrolytic efficiency and the ability to synthesize powerful inducers by genetically engineering Trichoderma reesei. RESULTS In our study, we employed a systematic genetic strategy to construct the carbon catabolite-derepressed strain T. reesei SCB18 to produce the cellulase complex that exhibited a strong cellulolytic capacity for biomass saccharification and an extraordinary high β-glucosidase (BGL) activity for cellulase-inducing disaccharides synthesis. We first identified the hypercellulolytic and uracil auxotrophic strain T. reesei SP4 as carbon catabolite repressed, and then deleted the carbon catabolite repressor gene cre1 in the genome. We found that the deletion of cre1 with the selectable marker pyrG led to a 72.6% increase in total cellulase activity, but a slight reduction in saccharification efficiency. To facilitate the following genetic modification, the marker pyrG was successfully removed by homologous recombination based on resistance to 5-FOA. Furthermore, the Aspergillus niger BGLA-encoding gene bglA was overexpressed, and the generated strain T. reesei SCB18 exhibited a 29.8% increase in total cellulase activity and a 51.3-fold enhancement in BGL activity (up to 103.9 IU/mL). We observed that the cellulase system of SCB18 showed significantly higher saccharification efficiency toward differently pretreated corncob residues than the control strains SDC11 and SP4. Moreover, the crude enzyme preparation from SCB18 with high BGL activity possessed strong transglycosylation ability to synthesize β-disaccharides from glucose. The transglycosylation product was finally utilized as the inducer for cellulase production, which provided a 63.0% increase in total cellulase activity compared to the frequently used soluble inducer, lactose. CONCLUSIONS In summary, we constructed a versatile cellulase system in T. reesei for efficient biomass saccharification and powerful cellulase inducer synthesis by combinational genetic manipulation of three distinct types of genes to achieve the customized cellulase production, thus providing a viable strategy for further strain improvement to reduce the cost of biomass-based biofuel production.
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Affiliation(s)
- Jia Gao
- State Key Laboratory of Microbial Technology, School of Life Sciences, Shandong University, Jinan, 250100 People’s Republic of China
| | - Yuanchao Qian
- State Key Laboratory of Microbial Technology, School of Life Sciences, Shandong University, Jinan, 250100 People’s Republic of China
| | - Yifan Wang
- State Key Laboratory of Microbial Technology, School of Life Sciences, Shandong University, Jinan, 250100 People’s Republic of China
| | - Yinbo Qu
- State Key Laboratory of Microbial Technology, School of Life Sciences, Shandong University, Jinan, 250100 People’s Republic of China
| | - Yaohua Zhong
- State Key Laboratory of Microbial Technology, School of Life Sciences, Shandong University, Jinan, 250100 People’s Republic of China
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Self-induction system for cellulase production by cellobiose produced from glucose in Rhizopus stolonifer. Sci Rep 2017; 7:10161. [PMID: 28860637 PMCID: PMC5579273 DOI: 10.1038/s41598-017-10964-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2017] [Accepted: 08/17/2017] [Indexed: 12/25/2022] Open
Abstract
Cellulolytic fungi have evolved a sophisticated genetic regulatory network of cellulase synthesis to adapt to the natural environment. Even in the absence of lignocellulose, it still secretes low levels of “constitutive” cellulase for standby application. However, the mechanisms of this constitutive expression remain incompletely understood. Here we identified a cellobiose synthetase (CBS) from Rhizopus stolonifer, which has the capacity to catalyse the synthesis of cellobiose from uridine diphosphate glucose (UDPG). Through the construction of R. stolonifer Δcbs strain, we found that CBS plays a key role in the synthesis of cellulase. Further analysis of cellulase synthesis under glucose culture reveals that the cellobiose-responsive regulator CLR1 was activated by CBS-synthesized cellobiose, thereby promoting the expression of CLR2 and finally opening the transcription of cellulase genes. Our results suggest that R. stolonifer can be induced by self-synthesized cellobiose to produce cellulase, which can be used to reconstruct the expression regulation network to achieve rapid production of cellulase using simple carbon source. Based on our data, the “constitutive expression” of cellulase actually derives from the induction of cellobiose that synthesized by CBS from carbohydrate metabolites, which updates our knowledge of cellulase, and provides a novel insight into the regulation of cellulase synthesis.
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Behera B, Sethi B, Mishra R, Dutta S, Thatoi H. Microbial cellulases - Diversity & biotechnology with reference to mangrove environment: A review. J Genet Eng Biotechnol 2017; 15:197-210. [PMID: 30647656 PMCID: PMC6296582 DOI: 10.1016/j.jgeb.2016.12.001] [Citation(s) in RCA: 76] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2016] [Accepted: 12/01/2016] [Indexed: 11/21/2022]
Abstract
Cellulose is an abundant natural biopolymer on earth, found as a major constituent of plant cell wall in lignocellulosic form. Unlike other compounds cellulose is not easily soluble in water hence enzymatic conversion of cellulose has become a key technology for biodegradation of lignocellulosic materials. Microorganisms such as aerobic bacteria, fungi, yeast and actinomycetes produce cellulase that degrade cellulose by hydrolysing the β-1, 4-glycosidic linkages of cellulose. In contrast to aerobic bacteria, anaerobic bacteria lack the ability to effectively penetrate into the cellulosic material which leads to the development of complexed cellulase systems called cellulosome. Among the different environments, the sediments of mangrove forests are suitable for exploring cellulose degrading microorganisms because of continuous input of cellulosic carbon in the form of litter which then acts as a substrate for decomposition by microbe. Understanding the importance of cellulase, the present article overviews the diversity of cellulolytic microbes from different mangrove environments around the world. The molecular mechanism related to cellulase gene regulation, expression and various biotechnological application of cellulase is also discussed.
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Affiliation(s)
- B.C. Behera
- Department of Biotechnology, North Orissa University, Baripada 757003, Odisha, India
| | - B.K. Sethi
- Department of Biotechnology, MITS School of Biotechnology, Bhubaneswar 751024, India
| | - R.R. Mishra
- Department of Biotechnology, MITS School of Biotechnology, Bhubaneswar 751024, India
| | - S.K. Dutta
- Department of Zoology, North Orissa University, Baripada 757003, Odisha, India
| | - H.N. Thatoi
- Department of Biotechnology, North Orissa University, Baripada 757003, Odisha, India
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Analysis of Light- and Carbon-Specific Transcriptomes Implicates a Class of G-Protein-Coupled Receptors in Cellulose Sensing. mSphere 2017; 2:mSphere00089-17. [PMID: 28497120 PMCID: PMC5425790 DOI: 10.1128/msphere.00089-17] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2017] [Accepted: 04/14/2017] [Indexed: 01/16/2023] Open
Abstract
In fungi, most metabolic processes are subject to regulation by light. For Trichoderma reesei, light-dependent regulation of cellulase gene expression is specifically shown. Therefore, we intended to unravel the relationship between regulation of enzymes by the carbon source and regulation of enzymes by light. Our two-dimensional analysis included inducing and repressing carbon sources which we used to compare light-specific regulation to dark-specific regulation and to rule out effects specific for a single carbon source. We found close connections with respect to gene regulation as well as significant differences in dealing with carbon in the environment in light and darkness. Moreover, our analyses showed an intricate regulation mechanism for substrate degradation potentially involving surface sensing and provide a basis for knowledge-based screening for strain improvement. In fungi, most metabolic processes are subject to regulation by light. Trichoderma reesei is adapted to degradation of plant cell walls and regulates production of the required enzymes in a manner dependent on the nutrient source and the light status. Here we investigated the interrelated relevance of two regulation levels of the transcriptome of T. reesei: light regulation and carbon source-dependent control. We show that the carbon source (cellulose, lactose, sophorose, glucose, or glycerol) is the major source of variation, with light having a modulating effect on transcript regulation. A total of 907 genes were regulated under cellulase-inducing conditions in light, and 947 genes were regulated in darkness, with 530 genes overlapping (1,324 in total). Only 218 of the 1,324 induction-specific genes were independent of light and not regulated by the BLR1, BLR2, and ENV1 photoreceptors. Analysis of the genomic distribution of genes regulated by light upon growth on cellulose revealed considerable overlap of light-regulated clusters with induction-specific clusters and carbohydrate-active enzyme (CAZyme) clusters. Further, we found evidence for the operation of a sensing mechanism for solid cellulosic substrates, with regulation of genes such as swo1, cip1, and cip2 or of genes encoding hydrophobins which is related to the cyclic AMP (cAMP)-dependent regulatory output of ENV1. We identified class XIII G-protein-coupled receptors (GPCRs) CSG1 and CSG2 in T. reesei as putative cellulose/glucose-sensing GPCRs. Our data indicate that the cellulase regulation pathway is bipartite, comprising a section corresponding to transcriptional regulation and one corresponding to posttranscriptional regulation, with the two connected by the function of CSG1. IMPORTANCE In fungi, most metabolic processes are subject to regulation by light. For Trichoderma reesei, light-dependent regulation of cellulase gene expression is specifically shown. Therefore, we intended to unravel the relationship between regulation of enzymes by the carbon source and regulation of enzymes by light. Our two-dimensional analysis included inducing and repressing carbon sources which we used to compare light-specific regulation to dark-specific regulation and to rule out effects specific for a single carbon source. We found close connections with respect to gene regulation as well as significant differences in dealing with carbon in the environment in light and darkness. Moreover, our analyses showed an intricate regulation mechanism for substrate degradation potentially involving surface sensing and provide a basis for knowledge-based screening for strain improvement.
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Zhang XY, Zi LH, Ge XM, Li YH, Liu CG, Bai FW. Development of Trichoderma reesei mutants by combined mutagenesis and induction of cellulase by low-cost corn starch hydrolysate. Process Biochem 2017. [DOI: 10.1016/j.procbio.2016.12.027] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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Li C, Lin F, Zhou L, Qin L, Li B, Zhou Z, Jin M, Chen Z. Cellulase hyper-production by Trichoderma reesei mutant SEU-7 on lactose. BIOTECHNOLOGY FOR BIOFUELS 2017; 10:228. [PMID: 29034003 PMCID: PMC5628480 DOI: 10.1186/s13068-017-0915-9] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2017] [Accepted: 09/23/2017] [Indexed: 05/13/2023]
Abstract
BACKGROUND The induction of cellulase production by insoluble carbon source cellulose was a common and efficient strategy, but has some drawbacks, such as difficult fermentation operation, substantial cellulase loss, long fermentation time, and high energy-consumption, resulting in high cost of cellulase production in industry. These drawbacks can be overcome if soluble carbon sources are utilized as the inducers for cellulase production. However, until now the induction efficiency of most soluble carbon sources, especially lactose and glucose, is still inferior to cellulose despite extensive efforts have been made by either optimizing the fermentation process or constructing the recombinant strains. Therefore, strain improvement by metabolic engineering for high induction efficiency of soluble carbon sources is of great interest. RESULTS Trichoderma reesei mutant SEU-7 was constructed from T. reesei RUT-C30 with the overexpression of endogenous gene β-glucosidase (BGL1) by insertional mutagenesis via Agrobacterium tumefaciens-mediated transformation (AMT). Compared to RUT-C30, SEU-7 displays substantially enhanced activities of both cellulase and hemicellulase when grown on either lactose or cellulose. The induction efficiency with lactose was found to be higher than cellulose in strain SEU-7. To the best of our knowledge, we achieved the highest FPase activity in SEU-7 in both batch culture (13.0 IU/mL) and fed-batch culture (47.0 IU/mL) on lactose. Moreover, SEU-7 displayed unrivaled pNPGase activity on lactose in both batch culture (81.0 IU/mL) and fed-batch culture (144.0 IU/mL) as compared to the other reported T. reesei strains in the literature grown in batch or fed-batch experiments on cellulose or lactose. This superiority of SEU-7 over RUT-C30 improves markedly the saccharification ability of SEU-7 on pretreated corn stover. The overexpression of gene BGL1 was found either at the mRNA or at the protein level in the mutant strains with increased cellulase production in comparison with RUT-C30, but only SEU-7 displayed much higher expression of gene BGL1 on lactose than on cellulose. Two copies of gene BGL1 were inserted into the chromosome of T. reesei SEU-7 between KI911141.1:347357 and KI911141.1:347979, replacing the original 623-bp fragment that is not within any genes' coding region. The qRT-PCR analysis revealed that the mRNA levels of both cellulase and hemicellulase were upregulated significantly in SEU-7, together with the MFS transporter CRT1 and the XYR1 nuclear importer KAP8. CONCLUSIONS Recombinant T. reesei SEU-7 displays hyper-production of both cellulase and hemicellulase on lactose with the highest FPase activity and pNPGase activity for T. reesei, enabling highly efficient saccharification of pretreated biomass. For the first time, the induction efficiency for cellulase production by lactose in T. reesei was reported to be higher than that by cellulose. This outperformance of T. reesei SEU-7, which is strain-specific, is attributed to both the overexpression of gene BGL and the collateral mutation. Moreover, the increased transcription levels of cellulase genes, the related transcription factors, and the MFS transporter CRT1 contribute to the outstanding cellulase production of SEU-7. Our research advances strain improvement to enhance the induction efficiency of soluble carbon sources to produce cost-effective cellulase and hemicellulase in industry.
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Affiliation(s)
- Chengcheng Li
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing, 210096 China
| | - Fengming Lin
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing, 210096 China
- 35 Jinxianghe Road, Xuanwu District, Nanjing, 210008 Jiangsu Province China
| | - Le Zhou
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing, 210096 China
| | - Lei Qin
- Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and Technology, Tianjin University, Weijin Road 92, Nankai District, Tianjin, 300072 People’s Republic of China
| | - Bingzhi Li
- Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and Technology, Tianjin University, Weijin Road 92, Nankai District, Tianjin, 300072 People’s Republic of China
| | - Zhihua Zhou
- Key Laboratory of Synthetic Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, 200032 China
| | - Mingjie Jin
- School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing, 210094 China
| | - Zhan Chen
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, MI 48109 USA
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(1→3)-α-d-Glucan from Fruiting Body and Mycelium ofCerrena unicolor(Bull.) Murrill: Structural Characterization and Use as a Novel Inducer of Mutanase. INT J POLYM SCI 2017. [DOI: 10.1155/2017/1249134] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Water-insoluble, alkali-soluble polysaccharide (marked as ASP) was extracted from the vegetative mycelium and fruiting body ofCerrena unicolorstrain. Monosaccharide examination of ASP demonstrated that the isolated biopolymer was composed mainly of glucose, xylose, and mannose monomers. The methylation investigation of studied polymers indicated that (1→3)-linkedα-D-Glcpis the major chain constituent (92.2% for glucans isolated from fruiting body and 90.1% from mycelium).1H NMR, FT-IR, and immunofluorescent labelling determinations confirmed that the polysaccharides isolated from both fruiting body and mycelium ofC. unicolorare (1→3)-α-d-glucans. The obtained (1→3)-α-d-glucans showed differences in viscosity and similar characteristics in optical rotations. (1→3)-α-d-Glucans extracted from mycelium and fruiting body ofC. unicolorwere also used as potential and specific inducers of mutanase synthesis byTrichoderma harzianum. The highest mutanase activity (0.38 U/mL) was obtained after induction of enzyme by (1→3)-α-d-glucan isolated from the mycelium ofC. unicolor, and this biopolymer has been suggested as a new alternative to streptococcal mutan for the mutanase induction inT. harzianum. (1→3)-α-d-Glucan-induced mutanase showed high hydrolysis potential in reaction with dextranase-pretreated mutan, where maximal degree of saccharification and solubilization of this bacterial homoglucan (83.1% and 78.4%, resp.) was reached in 3 h at 45°C.
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Benocci T, Aguilar-Pontes MV, Zhou M, Seiboth B, de Vries RP. Regulators of plant biomass degradation in ascomycetous fungi. BIOTECHNOLOGY FOR BIOFUELS 2017; 10:152. [PMID: 28616076 PMCID: PMC5468973 DOI: 10.1186/s13068-017-0841-x] [Citation(s) in RCA: 122] [Impact Index Per Article: 17.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2017] [Accepted: 06/06/2017] [Indexed: 05/05/2023]
Abstract
Fungi play a major role in the global carbon cycle because of their ability to utilize plant biomass (polysaccharides, proteins, and lignin) as carbon source. Due to the complexity and heterogenic composition of plant biomass, fungi need to produce a broad range of degrading enzymes, matching the composition of (part of) the prevalent substrate. This process is dependent on a network of regulators that not only control the extracellular enzymes that degrade the biomass, but also the metabolic pathways needed to metabolize the resulting monomers. This review will summarize the current knowledge on regulation of plant biomass utilization in fungi and compare the differences between fungal species, focusing in particular on the presence or absence of the regulators involved in this process.
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Affiliation(s)
- Tiziano Benocci
- Fungal Physiology, Westerdijk Fungal Biodiversity Institute & Fungal Molecular Physiology, Utrecht University, Uppsalalaan 8, 3584 CT Utrecht, The Netherlands
| | - Maria Victoria Aguilar-Pontes
- Fungal Physiology, Westerdijk Fungal Biodiversity Institute & Fungal Molecular Physiology, Utrecht University, Uppsalalaan 8, 3584 CT Utrecht, The Netherlands
| | - Miaomiao Zhou
- Fungal Physiology, Westerdijk Fungal Biodiversity Institute & Fungal Molecular Physiology, Utrecht University, Uppsalalaan 8, 3584 CT Utrecht, The Netherlands
| | - Bernhard Seiboth
- Research Area Biochemical Technology, Institute of Chemical and Biological Engineering, TU Wien, 1060 Vienna, Austria
| | - Ronald P. de Vries
- Fungal Physiology, Westerdijk Fungal Biodiversity Institute & Fungal Molecular Physiology, Utrecht University, Uppsalalaan 8, 3584 CT Utrecht, The Netherlands
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Kameshwar AKS, Qin W. Metadata Analysis of Phanerochaete chrysosporium Gene Expression Data Identified Common CAZymes Encoding Gene Expression Profiles Involved in Cellulose and Hemicellulose Degradation. Int J Biol Sci 2017; 13:85-99. [PMID: 28123349 PMCID: PMC5264264 DOI: 10.7150/ijbs.17390] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2016] [Accepted: 10/10/2016] [Indexed: 01/04/2023] Open
Abstract
In literature, extensive studies have been conducted on popular wood degrading white rot fungus, Phanerochaete chrysosporium about its lignin degrading mechanisms compared to the cellulose and hemicellulose degrading abilities. This study delineates cellulose and hemicellulose degrading mechanisms through large scale metadata analysis of P. chrysosporium gene expression data (retrieved from NCBI GEO) to understand the common expression patterns of differentially expressed genes when cultured on different growth substrates. Genes encoding glycoside hydrolase classes commonly expressed during breakdown of cellulose such as GH-5,6,7,9,44,45,48 and hemicellulose are GH-2,8,10,11,26,30,43,47 were found to be highly expressed among varied growth conditions including simple customized and complex natural plant biomass growth mediums. Genes encoding carbohydrate esterase class enzymes CE (1,4,8,9,15,16) polysaccharide lyase class enzymes PL-8 and PL-14, and glycosyl transferases classes GT (1,2,4,8,15,20,35,39,48) were differentially expressed in natural plant biomass growth mediums. Based on these results, P. chrysosporium, on natural plant biomass substrates was found to express lignin and hemicellulose degrading enzymes more than cellulolytic enzymes except GH-61 (LPMO) class enzymes, in early stages. It was observed that the fate of P. chrysosporium transcriptome is significantly affected by the wood substrate provided. We believe, the gene expression findings in this study plays crucial role in developing genetically efficient microbe with effective cellulose and hemicellulose degradation abilities.
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Affiliation(s)
| | - Wensheng Qin
- Department of Biology, Lakehead University, 955 Oliver Road, Thunder Bay, Ontario, P7B 5E1, Canada
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41
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Boudabbous M, Saibi W, Bouallagui Z, Dardouri M, Sayadi S, Belghith H, Mechichi T, Gargouri A. Fast activated charcoal prepurification of Fusarium solani β-glucosidase for an efficient oleuropein bioconversion. Prep Biochem Biotechnol 2016; 47:185-191. [DOI: 10.1080/10826068.2016.1201679] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Affiliation(s)
- Manel Boudabbous
- Laboratory of Molecular Biotechnology of Eucaryotes, Centre of Biotechnology of Sfax (CBS), University of Sfax, Sfax, Tunisia
| | - Walid Saibi
- Biotechnology and Plant Improvement Laboratory, Centre of Biotechnology of Sfax (CBS), University of Sfax, Sfax, Tunisia
| | - Zouhaier Bouallagui
- Environmental Bioprocesses Laboratory, Centre of Biotechnology of Sfax (CBS), University of Sfax, Sfax, Tunisia
| | - Mosbeh Dardouri
- Laboratory of Molecular Biotechnology of Eucaryotes, Centre of Biotechnology of Sfax (CBS), University of Sfax, Sfax, Tunisia
| | - Sami Sayadi
- Environmental Bioprocesses Laboratory, Centre of Biotechnology of Sfax (CBS), University of Sfax, Sfax, Tunisia
| | - Hafedh Belghith
- Laboratory of Molecular Biotechnology of Eucaryotes, Centre of Biotechnology of Sfax (CBS), University of Sfax, Sfax, Tunisia
| | - Tahar Mechichi
- Laboratory of Enzyme Engineering and Microbiology, ENIS, University of Sfax, Sfax, Tunisia
| | - Ali Gargouri
- Laboratory of Molecular Biotechnology of Eucaryotes, Centre of Biotechnology of Sfax (CBS), University of Sfax, Sfax, Tunisia
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42
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Reilly MC, Magnuson JK, Baker SE. Approaches to understanding protein hypersecretion in fungi. FUNGAL BIOL REV 2016. [DOI: 10.1016/j.fbr.2016.06.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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43
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44
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Antonov E, Wirth S, Gerlach T, Schlembach I, Rosenbaum MA, Regestein L, Büchs J. Efficient evaluation of cellulose digestibility by Trichoderma reesei Rut-C30 cultures in online monitored shake flasks. Microb Cell Fact 2016; 15:164. [PMID: 27686382 PMCID: PMC5043636 DOI: 10.1186/s12934-016-0567-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2016] [Accepted: 09/22/2016] [Indexed: 11/10/2022] Open
Abstract
Background Pretreated lignocellulosic biomass is considered as a suitable feedstock for the sustainable production of chemicals. However, the recalcitrant nature of cellulose often results in very cost-intensive overall production processes. A promising concept to reduce the costs is consolidated bioprocessing, which integrates in a single step cellulase production, cellulose hydrolysis, and fermentative conversion of produced sugars into a valuable product. This approach, however, requires assessing the digestibility of the applied celluloses and, thus, the released sugar amount during the fermentation. Since the released sugars are completely taken up by Trichoderma reesei Rut-C30 and the sugar consumption is stoichiometrically coupled to oxygen uptake, the respiration activity was measured to evaluate the digestibility of cellulose. Results The method was successfully tested on commercial cellulosic substrates identifying a correlation between the respiration activity and the crystallinity of the substrate. Pulse experiments with cellulose and cellulases suggested that the respiration activity of T. reesei on cellulose can be divided into two distinct phases, one limited by enzyme activity and one by cellulose-binding-sites. The impact of known (cellobiose, sophorose, urea, tween 80, peptone) and new (miscanthus steepwater) compounds enhancing cellulase production was evaluated. Furthermore, the influence of two different pretreatment methods, the OrganoCat and OrganoSolv process, on the digestibility of beech wood saw dust was tested. Conclusions The introduced method allows an online evaluation of cellulose digestibility in complex and non-complex cultivation media. As the measurements are performed under fermentation conditions, it is a valuable tool to test different types of cellulose for consolidated bioprocessing applications. Furthermore, the method can be applied to identify new compounds, which influence cellulase production. Electronic supplementary material The online version of this article (doi:10.1186/s12934-016-0567-7) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Elena Antonov
- AVT‑Biochemical Engineering, RWTH Aachen University, Worringerweg 1, 52074, Aachen, Germany
| | - Steffen Wirth
- AVT‑Biochemical Engineering, RWTH Aachen University, Worringerweg 1, 52074, Aachen, Germany
| | - Tim Gerlach
- AVT‑Biochemical Engineering, RWTH Aachen University, Worringerweg 1, 52074, Aachen, Germany
| | - Ivan Schlembach
- Institute of Applied Microbiology, RWTH Aachen University, Worringerweg 1, 52074, Aachen, Germany
| | - Miriam A Rosenbaum
- Institute of Applied Microbiology, RWTH Aachen University, Worringerweg 1, 52074, Aachen, Germany
| | - Lars Regestein
- AVT‑Biochemical Engineering, RWTH Aachen University, Worringerweg 1, 52074, Aachen, Germany
| | - Jochen Büchs
- AVT‑Biochemical Engineering, RWTH Aachen University, Worringerweg 1, 52074, Aachen, Germany.
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45
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Li Y, Liu C, Bai F, Zhao X. Overproduction of cellulase by Trichoderma reesei RUT C30 through batch-feeding of synthesized low-cost sugar mixture. BIORESOURCE TECHNOLOGY 2016; 216:503-10. [PMID: 27268435 DOI: 10.1016/j.biortech.2016.05.108] [Citation(s) in RCA: 71] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2016] [Revised: 05/25/2016] [Accepted: 05/26/2016] [Indexed: 05/05/2023]
Abstract
Cellulase is a prerequisite for the bioconversion of lignocellulosic biomass, but its high cost presents the biggest challenge. In this article, low-cost mixture was produced from glucose through the transglycosylation reaction catalyzed by β-glucosidase for cellulase overproduction by Trichodema reesei RUT C30. As a result, cellulase titer of 90.3FPU/mL, which was more than 10 folds of that achieved with lactose as inducer, was achieved at 144h. Meanwhile, cellulase productivity was drastically increased to 627.1FPU/L/h, at least 3-5 folds higher than previously reported by the fungal species. The crude enzyme was further tested by hydrolyzing NaOH-pretreated corn stover with 15% solid loading, and 96.6g/L glucose was released with 92.6% sugar yield at 96h and 44.8g/L ethanol was obtained.
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Affiliation(s)
- Yonghao Li
- School of Life Science and Biotechnology, Dalian University of Technology, Dalian 116023, China.
| | - Chenguang Liu
- State Key Laboratory of Microbial Metabolism & School of Life Science and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China.
| | - Fengwu Bai
- School of Life Science and Biotechnology, Dalian University of Technology, Dalian 116023, China; State Key Laboratory of Microbial Metabolism & School of Life Science and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China.
| | - Xinqing Zhao
- State Key Laboratory of Microbial Metabolism & School of Life Science and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China.
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46
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47
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Bischof RH, Ramoni J, Seiboth B. Cellulases and beyond: the first 70 years of the enzyme producer Trichoderma reesei. Microb Cell Fact 2016; 15:106. [PMID: 27287427 PMCID: PMC4902900 DOI: 10.1186/s12934-016-0507-6] [Citation(s) in RCA: 280] [Impact Index Per Article: 35.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2016] [Accepted: 06/01/2016] [Indexed: 11/10/2022] Open
Abstract
More than 70 years ago, the filamentous ascomycete Trichoderma reesei was isolated on the Solomon Islands due to its ability to degrade and thrive on cellulose containing fabrics. This trait that relies on its secreted cellulases is nowadays exploited by several industries. Most prominently in biorefineries which use T. reesei enzymes to saccharify lignocellulose from renewable plant biomass in order to produce biobased fuels and chemicals. In this review we summarize important milestones of the development of T. reesei as the leading production host for biorefinery enzymes, and discuss emerging trends in strain engineering. Trichoderma reesei has very recently also been proposed as a consolidated bioprocessing organism capable of direct conversion of biopolymeric substrates to desired products. We therefore cover this topic by reviewing novel approaches in metabolic engineering of T. reesei.
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Affiliation(s)
- Robert H Bischof
- Austrian Centre of Industrial Biotechnology (ACIB) GmbH c/o Institute of Chemical Engineering, TU Wien, Gumpendorferstraße 1a, 1060, Vienna, Austria
| | - Jonas Ramoni
- Molecular Biotechnology, Research Area Biochemical Technology, Institute of Chemical Engineering, TU Wien, Gumpendorferstraße 1a, 1060, Vienna, Austria
| | - Bernhard Seiboth
- Austrian Centre of Industrial Biotechnology (ACIB) GmbH c/o Institute of Chemical Engineering, TU Wien, Gumpendorferstraße 1a, 1060, Vienna, Austria. .,Molecular Biotechnology, Research Area Biochemical Technology, Institute of Chemical Engineering, TU Wien, Gumpendorferstraße 1a, 1060, Vienna, Austria.
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48
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Al-Jasim A, Davis M, Cossar D, Miller T, Humphreys P, Laws AP. Isolation of sophorose during sophorolipid production and studies of its stability in aqueous alkali: epimerisation of sophorose to 2-O-β-D-glucopyranosyl-D-mannose. Carbohydr Res 2016; 421:46-54. [PMID: 26774878 DOI: 10.1016/j.carres.2015.12.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2015] [Revised: 11/03/2015] [Accepted: 12/03/2015] [Indexed: 10/22/2022]
Abstract
NMR and anion exchange chromatography analysis of the waste streams generated during the commercial production of sophorolipids by the yeast Candida bombicola identified the presence of small but significant quantities (1% w/v) of free sophorose. Sophorose, a valuable disaccharide, was isolated from the aqueous wastes using a simple extraction procedure and was purified by chromatography on a carbon celite column providing easy access to large quantities of the disaccharide. Experiments were undertaken to identify the origin of sophorose and it is likely that acetylated sophorose derivatives were produced by an enzyme catalysed hydrolysis of the glucosyl-lipid bond of sophorolipids; the acetylated sophorose derivatives then undergo hydrolysis to release the parent disaccharide. Treatment of sophorose with aqueous alkali at elevated temperatures (0.1M NaOH at 50 °C) resulted in C2-epimerisation of the terminal reducing sugar and its conversion to the corresponding 2-O-β-D-glucopyranosyl-D-mannose which was isolated and characterised. In aqueous alkaline solution β-(1,2)-linked glycosidic bonds do not undergo either hydrolysis or peeling reactions.
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Affiliation(s)
- Ammar Al-Jasim
- Department of Chemical Sciences, School of Applied Sciences, University of Huddersfield, Queensgate, Huddersfield HD1 3DH, United Kingdom
| | - Mark Davis
- Department of Chemical Sciences, School of Applied Sciences, University of Huddersfield, Queensgate, Huddersfield HD1 3DH, United Kingdom
| | - Douglas Cossar
- Croda Biotechnology, Foundary Lane, Ditton, Widnes, Cheshire WA8 8UB, United Kingdom
| | - Timothy Miller
- Croda Biotechnology, Foundary Lane, Ditton, Widnes, Cheshire WA8 8UB, United Kingdom
| | - Paul Humphreys
- Department of Biological Sciences, School of Applied Sciences, University of Huddersfield, Queensgate, Huddersfield HD1 3DH, United Kingdom
| | - Andrew P Laws
- Department of Chemical Sciences, School of Applied Sciences, University of Huddersfield, Queensgate, Huddersfield HD1 3DH, United Kingdom.
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Guo B, Sato N, Biely P, Amano Y, Nozaki K. Comparison of catalytic properties of multiple β-glucosidases of Trichoderma reesei. Appl Microbiol Biotechnol 2016; 100:4959-68. [PMID: 26846743 DOI: 10.1007/s00253-016-7342-x] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2015] [Revised: 01/17/2016] [Accepted: 01/19/2016] [Indexed: 11/27/2022]
Abstract
Ten putative Trichoderma reesei β-glucosidase (BGL) isozymes were heterologously expressed in Escherichia coli and Aspergillus oryzae and purified to homogeneity. Catalytic properties of nine enzymes which showed hydrolytic activity on cellobiose and p-nitrophenyl-β-D-glucopyranoside (pNPG) were investigated. Three BGLs, encoded by the genes cel3A, cel3B, and cel3E, contained a predicted signal peptide, showed higher hydrolytic activity on cello-oligosaccharides than on pNPG, and preferred longer oligosaccharides. Another three putative extracellular BGLs, Cel3B, Cel3F, and Cel3G, and two intracellular enzymes, Cel3C and Cel3D, exhibited preference for pNPG. Intracellular Cel1A showed the highest affinity for cellobiose as a typical cellobiase. Four BGLs, Cel3A, Cel3B, Cel3E, Cel1A, that showed high activity against cello-oligosaccharides were capable of catalyzing transglycosylation reactions from cellobiose, leading to formation of cellotriose and isomeric glucobioses. While Cel3A, Cel3B, and Cel3E synthesized mainly gentiobiose, glycosyl transfer reactions of Cel1A led mainly to sophorose and laminaribiose. Conversion of cellobiose to sophorose by Cel1A reached about 3.6 and 10 % at 1 and 10 % cellobiose concentration, respectively. The formation and persistence of individual cellobiose isomers in incubation mixtures of four BGLs (Cel3A, Cel3B, Cel3E, and Cel1A) with cellobiose correlated well with the k cat values for isomeric glucobioses. Cel1A also showed the lowest sensitivity to inhibition by glucose. Based on all studied catalytic properties, Cel1A appears to be unambiguously the best candidate for site-directed mutations or directed evolution toward improvement of activity, thermostability, and, eventually, efficiency of sophorose synthesis.
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Affiliation(s)
- Boyang Guo
- Department of Bioscience and Textile Technology, Interdisciplinary Graduate School of Science and Technology, Shinshu University, 4-17-1 Wakasato, Nagano, 380-8553, Japan
| | - Nobuaki Sato
- Department of Bioscience and Textile Technology, Interdisciplinary Graduate School of Science and Technology, Shinshu University, 4-17-1 Wakasato, Nagano, 380-8553, Japan
| | - Peter Biely
- Institute of Chemistry, Slovak Academy of Sciences, 845 38, Bratislava, Slovakia
| | - Yoshihiko Amano
- Department of Bioscience and Textile Technology, Interdisciplinary Graduate School of Science and Technology, Shinshu University, 4-17-1 Wakasato, Nagano, 380-8553, Japan
| | - Kouichi Nozaki
- Department of Bioscience and Textile Technology, Interdisciplinary Graduate School of Science and Technology, Shinshu University, 4-17-1 Wakasato, Nagano, 380-8553, Japan.
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Guo B, Amano Y, Nozaki K. Improvements in Glucose Sensitivity and Stability of Trichoderma reesei β-Glucosidase Using Site-Directed Mutagenesis. PLoS One 2016; 11:e0147301. [PMID: 26790148 PMCID: PMC4720395 DOI: 10.1371/journal.pone.0147301] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2015] [Accepted: 01/02/2016] [Indexed: 01/07/2023] Open
Abstract
Glucose sensitivity and pH and thermal stabilities of Trichoderma reesei Cel1A (Bgl II) were improved by site-directed mutagenesis of only two amino acid residues (L167W or P172L) at the entrance of the active site. The Cel1A mutant showed high glucose tolerance (50% of inhibitory concentration = 650 mM), glucose stimulation (2.0 fold at 50 mM glucose), and enhanced specific activity (2.4-fold) compared with those of the wild-type Cel1A. Furthermore, the mutant enzyme showed stability at a wide pH range of 4.5–9.0 and possessed high thermal stability up to 50°C with 80% of the residual activities compared with the stability seen at the pH range of 6.5–7.0 and temperatures of up to 40°C in the wild-type Cel1A. Kinetic studies for hydrolysis revealed that the Cel1A mutant was competitively inhibited by glucose at similar levels as the wild-type enzyme. Additionally, the mutant enzyme exhibited substrate inhibition, which gradually disappeared with an increasing glucose concentration. These data suggest that the glucose stimulation was caused by relieve the substrate inhibition in the presence of glucose. To conclude, all the properties improved by the mutagenesis would be great advantages in degradation of cellulosic biomass together with cellulases.
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Affiliation(s)
- Boyang Guo
- Department of Bioscience and Textile Technology, Interdisciplinary Graduate School of Science and Technology, Shinshu University, Nagano, Japan
| | - Yoshihiko Amano
- Department of Bioscience and Textile Technology, Interdisciplinary Graduate School of Science and Technology, Shinshu University, Nagano, Japan
| | - Kouichi Nozaki
- Department of Bioscience and Textile Technology, Interdisciplinary Graduate School of Science and Technology, Shinshu University, Nagano, Japan
- * E-mail:
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